Can anyone help me, please?

30cm

Step-by-step explanation:

First I added 6 and 13 to get 19 then i said that they were going straight down to measure the sides so that means you need to multiply 5 times 2 and get 10 but the sides are tilted so if the sides are tilted then you need to add a half more for each because they are actually a little bit bigger then what they are saying so now you have 5 1/2 plus 5 1/2 and that gets you to 11 and 11 plus 19 is 30

hope this helps!

Please mark me as brainliest

x= -3 and

step-by-step explanation:

to find the roots of a cubic, use division or factoring to find the factors then set equal to 0. as this is a difference of cubes, it factors into

where a is the cube root of .

here   this is 27 and the cube root of 27 is 3. so we write using the form:

.

set each factor to 0 and solve for x.

x-3=0

x=3

the quadratic expression does not factor and must be solved using the quadratic formula.

where a = 1, b=3, and c=9

this cubic has two complex roots.